Summary of Work: This project focuses on menstrual cycle characteristics, menarche, menopause, and pregnancy history as risk factors for diseases hormonally-mediated diseases (e.g. osteoporosis, coronary heart disease) and diseases that only effect women (e.g., ovarian cancer). 1) We are using a unique data source: prospectively collected menstrual cycle data from 997 college-aged women who participated in a menstrual diary study in the 1930's. Follow-up of the health status of members of this cohort was conducted in 1989-91 using a mailed questionnaire and death certificate searches. We have analyzed the association between menstrual cycle characteristics and peri- and post- menopausal fractures: Wrist fracture (n=62) risk increased with increasing age at menarche (odds ratio, OR, 3.3, 95%CI (1.7-6.2) for menarche age greater than or equal to 14 compared to 12 -13 years old) and increasing mean cycle length at age 28 - 32 (OR 2.2 (95% CI (1.0-4.9) for > 30.5 days compared to 26.6 - 30.5 days), and increasing bleeding duration (OR 1.7 for > 6.0 days compared to 4.7 - 6.0 days). Similar results were seen in analyses of the combined wrist, hip, or vertebral fracture group (n=92). We are currently analyzing the menstrual, reproductive, and menopausal risk factors in relation to risk of coronary heart disease and ovarall mortality in the cohort. 2) We are examining the association between risk of ovarian cancer and age at first birth, age at last birth, and menopausal status using data from 4 previously conducted case-control studies. These studies include a wide age range of ovarian cancer cases (ages 18-78) and allow us to examine the potential modifying or confounding effects of family history, oral contraceptive use, tubal ligation, and infertility.